This invention relates to crystallized glass articles having surface patterns imparting to them an appearance such as granite, marble or other natural stones.
Crystallized glasses formed by the heat treatment of glasses have attracted great attention as heat-resistant, incombustible wall materials for buildings and the like because of great mechanical strength, excellent heat resistance and excellent efflorescence resistance. Especially, a crystallized glass obtained by heat-treating molded article of a glass of the CaO-Al.sub.2 O.sub.3 -SiO.sub.2 type free of a nucleating agent, as disclosed in U.S. Patent No. 3,761,235, has a beautiful appearance of a pattern resembling that of a natural stone material such as marble, due to needle-like crystals of .beta.-wollastonite being precipitated and grown to extend from the glass surface into the interior. Such a crystallized glass is a very valuable heat-resistant, incombustible wall material.
Further, a glass composition of this type improved in the workability of the crystallizable glass, the crystallizing rate and the like is disclosed in commonly owned copending U.S. Pat. application No. 539,160 filed Jan. 2, 1975.
In each of above patent Patent Application, the primary object is to obtain an appearance resembling that of marble.